61810491 has 8 divisors (see below), whose sum is σ = 82960384. Its totient is φ = 40933800.

The previous prime is 61810481. The next prime is 61810501. The reversal of 61810491 is 19401816.

It is an interprime number because it is at equal distance from previous prime (61810481) and next prime (61810501).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 61810491 - 2²³ = 53421883 is a prime.

It is a super-2 number, since 2×61810491² = 7641073595322162, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61810421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 67771 + ... + 68676.

It is an arithmetic number, because the mean of its divisors is an integer number (10370048).

Almost surely, 2^61810491 is an apocalyptic number.

61810491 is a deficient number, since it is larger than the sum of its proper divisors (21149893).

61810491 is a wasteful number, since it uses less digits than its factorization.

61810491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136601.

The product of its (nonzero) digits is 1728, while the sum is 30.

The square root of 61810491 is about 7861.9648307532. The cubic root of 61810491 is about 395.3854934477.

Adding to 61810491 its sum of digits (30), we get a triangular number (61810521 = T₁₁₁₁₈).

The spelling of 61810491 in words is "sixty-one million, eight hundred ten thousand, four hundred ninety-one".